Partial Mantel correlations between community structure, geographical distances, and environmental variables.

The partial Mantel statistic r(SG.E) estimates the Spearman rank correlation between S (OTU similarity) and G matrices (geographical distance) while controlling for the effect of environmental distances (E). Likewise, r(SE.G) calculates the Spearman rank correlation between matrices S (OTU similarity) and E (environmental distance) while controlling for the effect of geographical distance (G). Geographical matrix (G) contained spatial distances among floodplain samples. Significance was calculated from 99999 randomized permutations of one of the dissimilarity matrices (*P-valuePartial Mantel correlations between community structure, geographical distances, and environmental variables.